The objective of this protocol is to use a case-control paradigm to compare the response to an intravenous administration of kisspeptin in individuals with and without post-covid-19 syndrome. The study subjects will receive a single bolus of kisspeptin. This study will utilize the technique of frequent blood sampling (q10 minutes) to provide detailed neuroendocrine characterization of endogenous LH secretion before and after kisspeptin administration. This frequency of blood sampling is required to define the features of LH pulses.

Delivery of Interventions: * 1-2 hours of q10 minute blood sampling * Administration of a single kisspeptin bolus in a dosing range of 0.313 - 13.19 μg/kg